Improvement in apparatus for evaporating salt



W. T. CLOUGH.

Evaporating Pan.

Patented Aug. 26. 1856.

HIV

Inventor,

NITED STATES P TENT OFFICEQ WILLIAMT. eLoUeH, 0F NEWARK, NEW JERSEY.

Specification forming part of Letters Patent No. l5,59, dated August 26, 1856.

cation.

Before dcscri bing my invention,I would simply state that it is analogous to my furnace for concentrating sulphuric acid, inasmuch as I evaporate by means of radiated heat from a hot surface being placed 'above the liquor; hence I shall confine myself to the new arrangement, which is as follows:

, Figure 1 is a horizontal sectional view of the furnace having the front side taken off for the purpose of showing the pans A A A A and the hot-air chamber B, and fines O O, for the admission of the hot air from the chamber B into the evaporating-pans. These flues are regulated by ordinary dampers in the back side of the furnace. The liquid is also admitted into the pans through one or more of these holes by means of pipes through the back wall of the furnace, or otherwise. Fig. 2 is a transverse section of the furnace, showing one pan, A", with a metallic covering, (or fire-tiles) D D, and the fire-flue E; also showing the hotair chamber or flue B, and its communication, with the evaporating-pans A A, through the transverse fines O O at the back of the pans.

Letters F F are small fines or pipes running from the pans into the horizontal fine G, along the top near the front of the furnace,and connecting with the smokestack.

His the pocket or apron to receive the salt.

From the rapid destruction of the metallic pans or kettles (employed in the evaporation of common salt or other liquids) by the application of heat to the under side or bottom of the pans, which causes an inerustation of the salt (upon the bottom of the pans) during the process of evaporation,whieh is productive of much loss to the manufacturer, not only the loss of the salt and the destruction of the kettles, but it requires a much greater amount of mean time the bottom of the pan is heated to a red heat, fracture or a rapid burning away of the pan is-the consequence. By my process I am enabled to prevent the incrnstation of the salt upon the pans, and to make the production of salt a continuous process, thus saving time, labor, and the destruction of pans. The heat being applied upon the upper surfaeeof the brine, the crystals of salt are formed by the abstraction of the water of solution, they fall to the bottom of the pan, which is cool, and from time to time are raked into the pocket H of the pans in front of the furnace; from thence are placed on drainers to dry.

By my process of evaporation I am enabled to produce a better quality of salt than by the old method of applying the heat to the bot tom of the pans. The sun-evaporated salt is always the purest, to which process mine is very analogous.

I have arranged a series of cast or wrought iron pans, A A, side by side, and covercdthem with iron plates or arches, D D, of firetiles. Immediately over these plates is the fire-fine E E, direct from the fire-grate to the smoke-stack I. Next to the fire-arch J is the hot-air chamber or fine B, that connects with the transverse hot-air fines O O, at the back of the pans A A, as shown at O G, Figs. 1 and 2. By this arrangement I expedite the evaporation. The steam and hot air from the pans are conveyed into a fine communicating with the smoke-stack I, the draft of which has a tendency to draw the hot air from the (hotair) chamber B, along with the steam evaporated from the saline mixture, through the flue G to the stack;

Immediately in front and attached to the pans I have formed an apron or pocket, as shown at H, Fig. 2, into which the salt is raked through an opening in the front of each pan. This opening is kept closed while the furnace is in operation, excepting for raking out the salt, by means of an ordinary sheet-iron slide or hinged door, (or hung on a rod and made to drop four or five inches into the liquor in the pocket,) thus preventing the cold external air from going into the furnace. Then the ,F F, arranged and combined withthe pans brinebecoines saturated with bittern, a siphon A A A, in the manner and for the'purpose set in the pocket will empty any one of the specified.

pans Without stopping the working of the In testimony whereof I hereunto subscribe others. my name in the presence of two witnesses. Therefore I do not claim the individual parts i of the above-described apparatus; but OLOUGH' What I claim, and wish to secure by Letters Witnesses: Patent of the United States, is JAMEs'P. MOLEAN The apron H, chamber B, and escape-fines ANNE S. MoLEAN. 

